Question concerning db sensitivity

There is no truth to this. Speaker sensitivity has no more to do with sound quality than amplifier power, which is zilch.

John

Someone recently told me that in their experience, in general, that the higher the db sensitivity of a given speaker, the more you sacrifice in terms of sound. In other words, lower db rated speakers [ 86-88 ] typically sound better. Any thoughts on this?

Yes this is true. This matches my experience with conventional box speakers. As generalizations go, this is actually quite a good rule of thumb (there are exceptions).

The light weight and rigid diaphragm structures necessary to produce very high efficiencies (ceramic, metal etc.) generally result in an under damped system (high Q - resonances). Furthermore, the highest efficiencies are often achieved by using a long voice coil in short magnetic gap which means the linear operating range of the driver excursion is modest and it is less efficient at dissipating heat than a short coil mounted in a more expensive massive magnet assembly; this results in more distortion and compression at modest SPL's and the speaker will sound positively dull and boomy at high SPL's.

I haven't mentioned horns here, all I will say is that I have seen plenty of horns used for sound reinforcement but rarely, if ever, have I seen a horn used as a professional studio monitor; this fact alone speaks volumes about the fidelity of high efficiency horns...

There is no truth to this. Speaker sensitivity has no more to do with sound quality than amplifier power, which is zilch.

John,

Your statement is as one sided as it is inaccurate. How can you possibly say that speaker sensitivity and amplifier power have NOTHING at all to do with sound quality?

Perhaps you do not regard distortion, resonance, dynamic range and accuracy at typical music SPL's as being in anyway related to sound quality...in which case I could understand your extreme position much better.

The only thing that can be generalized is that a high sensitivity speaker, all else being equal (never is), will have a more limited low frequency response than a lower dB speaker of the same size. This means nothing with respect to sound quality, unless that "someone" uses low frequency extension as the only yardstick.

I went from Thiel 1.5s to Coincident Conquests. Why? Sensitivity! My tube amps didn't like the Thiels too much. I honestly feel that both speakers are very similar in quality but going from 88db to 94 db allowed me to use any tube amp I wanted.

Your statement is as one sided as it is inaccurate. How can you possibly say that speaker sensitivity and amplifier power have NOTHING at all to do with sound quality?

Shadorne

I've heard good quality, low sensitivity speakers, I've heard good quality, high sensitivity speakers. I've heard poor quality, low sensitivity speakers, I've heard poor quality, high sensitivity speakers. Same for amplifiers. In fact, if the first watt sounds of poor quality, who would want anymore?

From my 30 years in the hobby, I feel that sensitivity in a speaker and power in an amplifier are as important to quality sound as gas mileage and tank size are to a quality automobile. When car shopping, how many focus on gas mileage and gas tank size as being the key factor in the quality of the car? Sure, a big tank with good gas mileage will take you further, but does it really have anything to do with the quality of your vehicle or the enjoyment you gain from driving it?

That's my $0.02, as always YMMV.

John,

Ok I understand this has simply been your experience. I misread your statement as a fact or well known "truth".

Sorry...

seems like some very different opinions. For some reason I would have thought this issue was less subjective than others. Hmmm?

Adman227,

For some reason I would have thought this issue was less subjective than others

Everything in audio is highly subjective, which is why I took the time to qualify my reply with a description of a couple of the general measurable issues/compromises in the choice of high or low speaker effciency. Of course, there are many more issues which can lead to many exceptions but then this would no longer be a "generalization" if we were to plunge into great details.

If this information helps guide you to choose a speaker - Great!
A "generalization" like this, however, is absolutely no substute for auditioning and narrowing your choice to speakers that you personally like the sound of, which I suspect was really John and Tvad's point.

Considering the strength of Shadorne's position and my strong preference for high-efficiency designs (as well as many others) I'd say this is no less divisive than any other of our tussels.

I've heard lots of folks say that high efficiency designs are better (they're the underdog, after all). This is the first time I've ever heard a blanket statement that low-efficiency is inherently superior.

John, please reread the qoute " SOMEONE recently told me that in THEIR experience, in GENRAL, that the higher the dB sensitivity of a given speaker, the more you sacrafice in terms of sound. In other words, lower dB rated speakers [86-88] TYPICALLY sound better. Any thoughts on this?"
CAPS by me.
BTW, this parallels my experience as well.
Obviously, your thoughts indicates that this contradicts your experience.
I guess our milage does indeed vary.
On another note, if one wanted to truly drive an off-road vehicle in the manner for which it was intended, and the intended location was was not near a filling station, such a vehicle might be purchased with consideration of fuel consumption and the size of the tank.

Assuming equal box size, the less efficient speaker will usually have deeper bass, or better bass transient response, or some combination thereof.

Peaks in the frequency response are more audible than dips, and the process of smoothing out a driver's frequency response by bringing down the peaks via equalzation in the crossover network inherently lowers the system's efficiency.

Cones that are heaviliy damped tend to sound smoother than lighter, less well damped cones. The heavier cones usually sound smoother, but may also sound less lively and detailed - so it's often a trade-off.

I would disagree with this statement: "In general, the higher the db sensitivity of a given speaker, the more you sacrifice in terms of sound." It's more complicated than that. There are trade-offs made either way, and which is the most desirable set of trade-offs depends on the specific application as well as - gasp - individual preference.

I believe that there are fairly large variations from one person to another in our tolerance for different types distortion, so you might not be bothered by the midrange forwardness that is driving me nuts while I'm oblivious to the power compression that ruins it for you.

Duke

sensitivity has nothing to do with quality. most loudspeakers are a collection of parts drivers, box,and crossovers. A bigger box usually better low freq extension; ported around 3 dbs more efficient so on and so on BUT sensitivity definatly has nothing to do with quality.

As usual I agree with my friend John(Jmcgrogan2).I Think it is a question of quality and system synergy.I recently sold a pair of Revel F-30 speakers that sounded great with my large Plinius solid state amp.When I switched to Consonance tube amps I found the more sensitive Soliloquy 6.3i speakers to be a better match.Both pair of speakers are excellent when paired with the proper ancillary equipment.

Larry

A "generalization" like this, however, is absolutely no substute for auditioning and narrowing your choice to speakers that you personally like the sound of, which I suspect was really John and Tvad's point.
Shadorne

Yes, now you have at least my POV nailed. Keep in mind, that I myself own speakers that are 89 db efficiency. However, I have heard many excellent higher efficient speaker designs as well.

Generally, there are no generalizations in the audio hobby. No one else can tell you what sounds good to you, you just have to listen for yourself......sorry.

John

The only thing that I've heard about high sensitivity speakers [95+ dB] is that one has to be more careful with the choice of upstream gear, especially the amplifier.

Jmcgrogan2 wrote: "Generally, there are no generalizations in the audio hobby."

LOL! That's great! I presume you did that on purpose.

There's a great deal of truth in that statement. One can find exceptions to most of the generalizations (and if I'd have said "to all of the generalizations", I'd have been over-generalizing!).

It is the high efficiency speakers that are smooth that are the most exciting. It is the low efficiency speakers with great dynamics that are most exciting. It is the box speakers that sound boxless, the horn speakers that sound hornless, and the planar speakers that can do deep bass and don't beam that are the most exciting. Seek out the innovative exceptions - they're out there!

Duke

I'll mention something to consider since it hasn't been addressed in the above posts. Higher sensitivity in a speaker will also result in louder power supply noise passed on to the speakers. This may or may not be audible at the listening position, but if you listen in the nearfield the noise can be substantial.

If you can hear idle hiss such as rf noise in an 85db speaker then consider bumping that noise up by 10db in a 95db speaker.

There is one small point that one can generalise on: the higher the sensitivity, the more uncompressed dynamic range you can have (note: you "CAN" have. You might not have in practise). How it sounds, is another matter.

First the obvious. Sound quality is completely subjective.
As I read it I think this generalization is probably from a source that thinks bass response is correlated with high quality. The SET single driver audio system may be nirvana, the truth, pure etc. to some, but the vast majority think they are hearing very thin sounding speakers. They are high efficiency speakers given that SET amps are as a rule low energy output signal. Admittedly a well designed high efficiency backloaded horn can make satisfying bass. However there is a strong prevalence that bassy sound is better sound if is not muddy, even amongst audiophiles. What are all these subs about? Not just HT.
BTW I think whomever said that pro monitors do not have horns in them should look at what is on the pro/studio market. Lots of horns. Beyond which they are voicing the sound for car radios and earspuds from portable compressed formats. Audiophile labels are almost irrelavent. Except to us. Unfortunately IMHO we don't represent significant money to the media.

BTW I think whomever said that pro monitors do not have horns in them should look at what is on the pro/studio market.

Mechans,

I meant real professional monitors for mixing/mastering in a studio....NOT sound reinforcement or for nightclubs or concert or myriad of speakers with the monikor "monitor" or "pro".

I think you will find that horns were popular in the 50's but eventually fell out of favor (in professional studios) in the 70's as non-horn designs began to achieve sufficient loudness levels for use as main monitors (mostly used to impress clients by playing back what they just played in a very realistic fashion).

Horns are almost completely out of the professional studio market as far as I can tell. They are almost never used as nearfields and only rarely used as main monitors.

Anyway, don't take my word for it, after all, many of my most accurate statements have been totally discredited/contradicted/distorted by one or another of the "experts" on these forums so what's new...

Perhaps this, from a person who is passionate about the Altec Lansing 604 horn designs (famous in the 40's), may convince you;

Studio Monitor Evolution

Jim,

Here is an example.

Take a classic famous well respected "hall of fame" type speaker like the Wilson Watt Puppy 7.

Look at the two distortion plots at 90 db SPL and at 95 db SPL (top curve is output SPL and bottom curve is THD+N SPL)

Notice that as the sound level is raised by 5 db SPL the distortion components increase by much more (8 or 9 db SPL)....this is always the case, even on great speakers such as this. The higher the output levels (towards realistic live sound) the relatively greater distortion ...until eventually the distortion becomes audible (and perceptively very loud). This point will vary for each system of amplifier and speaker but generally even small systems can be made to be perceived as sounding very loud (but in a small system it is mostly the harshness of distortion and not ACTUAL SPL level that gives the impression of loudness)

shadorne is right on

Shadorne Horns are used in studios I have built a fostex system with such for a known studio. I see lots of TAD horns in studios but most of the small monitors are still cones and domes keep in mind a good studio doesnt just use the small monitors, ussualy on the wall a set of compresion horns with BR bass will be in use.

I never had any real reason or knowledge to think this way but I always assumed less effecient speakers in high end models were probably better but harder to support with power.

Johnk,

Horns are used in studios.....usualy on the wall a set of compresion horns with BR bass will be in use.

I agree the horns are almost exclusively used for main monitors which are mainly used to impress clients at high SPL's.

I was trying to say that most nearfields for mixing and mastering do not use horns and that even for main monitors(the big soffit mounted beasts) there has been a significant shift away from horns ( a process that only begain in the 70's). Older studios may still have horns in place. Horns have not been entirely displaced from the studio.

Nearfield monitors are typically not prosound equivalents of high-end speakers. Natural sound is not necessarily a high priority for a nearfield monitor.

Main monitors on the other hand do place a high emphasis on sound quality. While it's true many studios use B&W or ATC speakers (the ATC midrange is short-horn loaded), TAD monitors are still in use in many studios. Genelecs use waveguides, which are a type of horn.

Horn loading of some type is more common than you may realize.

The coaxial units in speakers by Gradient, Tannoy, KEF, Pioneer (Model One, S-1EX and S-2EX), and others use the midbass driver's cone as a horn or waveguide for the tweeter. I'm presently learning more about this format, and have a coaxial-based speaker or two under development.

In many cases, the device or cabinet feature called a "waveguide" could just as well be called a "wide-pattern conical horn". Examples of such waveguide speakers include models by Amphion, Genelec, YGA, GedLee, SP Technology, Emerald Physics, and yours truly.

Finally, many modern horns are very low in coloration compared with earlier generation horns. Tractrix, hyperbolic, Le Cleac'h, oblate spherioid, bispherioidal, elliptical, quadratic, whatever the Oris is - these are some examples. Johnk, do you know what type of profile the Oris uses?

Once upon a time I administered a blind listening test involving a modern horn-type speaker. One of the listeners owned electrostats. In his notes, this listener commented that he suspected the speaker was an electrostat. I have demonstrated modern "waveguide" (wide-pattern conical horn) designs to literally hundreds of people, and not one has commented that he or she heard any cupped-hands or other horn-like colorations, and often I've specifically asked.

Duke

Duke oris is tactrix, your right about wave guides I see many monitors using shallow guides. The only time I heard the cuped hand sound is from a old edison theater horn that I installed a 2in driver in sounds fun loud very very directional but does have the cupped hand sound but its a primitive horn designed to make the most out of edison cylinders.Not hifi just so folks in back could hear the talkies.Could these myths about modern horn sound come from so long ago? I just dont hear this honk, cupped hands etc that folks say modern horns produce and since I have built and tried so many types designs transducers think I would of run into it;)

Duke,

Good point. Waveguide loaded mid ranges and tweeters are widely used everywhere even in nearfields. I draw a large distinction between these designs and traditional "compression" horns ....but like most things in this hobby many designs share some physical similarities.

Here is a good independent article on this subject (Ralph at AERONet). Waveguide Mid range Design

There are more details and a discussion of waveguide versus compression horns on this website (for those seriously interested...I realize details can tend to make most people's eyes glaze over in a hobby which is largely intended to be just a fun pastime).

Shadorne,

Very interesting site, thanks for the link. I've used that ATC midrange driver and agree that it is a very high quality unit. It doesn't really fit in with my present speaker design paradigm so I'm not using it any longer, but in my opinion its among the very best direct-radiator moving coil midranges in production today.

The article points out something that's often overlooked regarding the fabled ATC dome midrange - once it has been equalized, its efficiency is down to about 90 dB.

The article on waveguides is also quite informative. A large-radius lip at the mouth is indeed desireable, and any round horn or waveguide will have on-axis anomalies (in particular a hole) that's related to the dimensions, lip radius, and microphone distance. Whether the on-axis anomalies are audible depends on several factors, but I prefer to sidestep the issue by listening off axis.

I like a narrower pattern than what the author recommends. He seems to like 110 to 150 degrees, presumably in pursuit of a wide sweet spot. In my experience a 90 degree pattern will give you a very wide sweet spot provided you use a lot of toe-in, and also there is less pattern-width discrepancy in the top end when the tweeter does start to become directional.

The author takes the position that a direct radiator is superior to a compression driver because it has smoother response. I'll concede that its easier to get smooth-sounding response from a waveguide-loaded direct radiator, but it can be done with a compression driver as well (the ear is insentitive to narrow-band peaks and dips as long as they average out over a fairly short interval). And the compression driver will almost always have higher efficiency and better dynamic characteristics, which may or may not be desirable in a particular applicaiton (you don't want a big mismatch in power compression charactersitics between the woofer and tweeter). Having built prototype systems using both approaches I prefer the compression driver, but suitable ones are rare and even then they aren't easy to work with.

One of these days I'd like to see how a two-way with waveguide-loaded tweeter compares side-by-side with something like an ATC SCM-50.

Duke

One of these days I'd like to see how a two-way with waveguide-loaded tweeter compares side-by-side with something like an ATC SCM-50.

Yes that would be interesting.

ATC adapt a vifa tweeter with a short conical waveguide on the small two way SCM 20. The soft mid dome is grafted onto the woofer in this two way design. The woofer shape also appears to act as a mid waveguide as well as a woofer. The crossover is lower (2.8 Khz instead of 3.5 Khz, as on the SCM 50) probably because of cone breakup issues or driver beaming in the two way design. The dome may also act as a phase plug and help keep beaming issues above the crossover (this last bit is just my speculation).